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584 I. Zalud
However, recent advances in hCG determination
and ultrasound, especially TVS, have helped in its
early diagnosis and correct localization [48, 49]. TVS
has been reported to be of diagnostic value in differentiating
ovarian pregnancy from tubal pregnancy
[50]. The image of ovarian mass is characterized by a
double hyperechoic ring surrounding a small hypoechogenic
field. A case of twin ovarian pregnancy
diagnosis on TVS has also been reported [51]. Bontis
et al. have evaluated the criteria for diagnosis of ovarian
pregnancy based on currently available diagnostic
methods [52].
Abdominal Pregnancy
It accounts for 0.03% of ectopic pregnancies [40]. Its
diagnosis is often missed on TVS or delayed, as most
of these are secondary implantations occurring after
tubal rupture or abortion. In most of the cases abdominal
scanning is preferable. TVS may have a role
in suspected abdominal pregnancy by virtue of clear
depiction of the gestation sac outside the uterus. The
endocervical canal does not extend up to the placenta
but is present either posterior or anterior to it. Walls
of the lower uterine segment are seen opposed to
each other and not separated by the gestational sac.
Diagnostic Difficulties
The ultrasonologist should be aware of conditions
causing false-positive or false-negative Doppler ultrasound
diagnosis of ectopic pregnancy [32], which are
listed in Table 39.4. A false-positive diagnosis predominantly
comes from corpus luteum, but other adnexal
tumors may also be a source of error. Malignant
ovarian or tubal masses, endometriosis, or inflammation
can be a diagnostic challenge. Corpus luteum
can produce color and pulsed-wave Doppler
patterns that are similar and sometimes almost identical
to those seen with an ectopic pregnancy. Zalud
and Kurjak studied luteal blood flow in pregnant and
nonpregnant women [53]. Typical luteal low-impedance
blood flow was detected in 82.8% cases of normal
early pregnancy, 80.8% cases of ectopic pregnancy,
and 69.3% cases of nonpregnant women during
the luteal phase of the menstrual cycle. The lowest
RI (0.42Ô0.12) of luteal flow was found in nonpregnant
women, and the highest RI (0.53Ô0.09) was
seen with an early intrauterine pregnancy. The RI in
cases of ectopic pregnancy was 0.48 Ô 0.07. In 86.4%
of patients with proved ectopic pregnancy, luteal flow
was detected on the same side as the ectopic pregnancy.
This observation can be used as a guide when
searching for an ectopic pregnancy.
A false-negative result may arise from technical inadequacy
of the performed ultrasound scan, lack of
Table 39.4. Conditions affecting Doppler ultrasound findings
for ectopic pregnancy
False-positive findings
n Corpus luteum a
n Endometriosis
n Pelvic inflammatory disease
n Other adnexal masses or structures b
n Ovarian cancer
False-negative findings
n Very early ectopic pregnancy
n Avascular ectopic gestation
n Lack of experience of the technician
n Technical difficulties
n Nonvascularized ectopic pregnancy
n Patient noncompliance c
a The corpus luteum may create the impression of a saclike
structure because it is eccentrically located within the
ovary and surrounded by ovarian tissue.
b A thin-walled ovarian follicle; the small intestine; and tubal
pathologic conditions such as a fluid-containing hydrosalpinx.
c Patient is not lying very still.
experience, or the patient's noncompliance. Another
possibility is a nonvascularized ectopic gestation.
Noting that one-third of ectopic pregnancies showed
no evidence of detectable vascularity, Meyers and associates
investigated the hypothesis that this group
represented nonviable ectopic pregnancies [54]. They
studied them by comparing the serum b-hCG levels
in women with vascular and nonvascular ectopic
pregnancies. A statistically significant difference was
seen between the serum hCG level of those women
with ectopic pregnancies with vascularity compared
with those women without vascularity. The avascular
ectopic pregnancies showed low levels of serum b-
hCG, suggesting a nonthriving or dying embryo. We
diagnosed ectopic gestations routinely by color Doppler
sonography when the b-hCG level was below
1,000 IU/L. The impact of these observations on possible
conservative therapy has yet to be considered.
Management
Conservative Management
Initiation of conservative therapy for ectopic pregnancy
requires fulfillment of strict selection norms
[4]. The established criteria for patient selection are
listed in Table 39.5.
Conservative management of ectopic pregnancy includes:
(a) tubal-conserving surgery which is usually
performed laparoscopically; (b) expectant management;
and (c) medical management. The conservative
laparoscopic procedures for treatment of ectopic preg-